The present invention relates to a machine vise having two opposed movable jaws that will clamp two work pieces against oppositely facing surfaces of a common center-mounted fixed vise jaw. More particularly, a machine vise is disclosed having an actuator drive that rotates to displace the movable jaws toward the fixed jaw simultaneously to clamp the work pieces therebetween. The actuator drive, using fluid pressure, further displaces axially along its axis to simultaneously exert the final clamping forces on work pieces between the opposed jaw surfaces.
The concept of having a vise that has a body with a center fixed block and movable jaws that move toward this fixed block for holding work pieces has been shown in the prior art in various embodiments. For example, U.S. Pat. No. 4,934,674 discloses a two-station, single action vise. The vise has a body, a fixed center block having oppositely facing jaw plates, and movable jaws at opposite ends of the body that are moved by operation of a drive screw. The drive screw has left-hand threads for operating one of the movable jaws and right-hand threads for operating the other movable jaw. As the drive screw is rotated, both movable jaws move simultaneously toward the center block in order to clamp work pieces between facing plates of the center fixed block and the movable jaws. The drive screw and movable jaws also can be adjusted axially as an assembly with respect to the vise body to shift or adjust the movable jaws with respect to the fixed block in order to permit different sized parts to be clamped between each movable jaw and the fixed block.